Solution−Liquid−Solid Growth of Ternary Cu−In−Se Semiconductor Nanowires from Multiple- and Single-Source Precursors

Ternary CuInSe2 nanowires were synthesized for the first time by the solution−liquid−solid (SLS) mechanism. Here, both metal−organic multiple- and single-source molecular precursors were thermally decomposed in the presence of molten metal nanoparticles and coordinating ligands. The nature of the precursormultiple- compared to single-source (wherein Cu−Se−In bonds are effectively preformed)as well as the choice of coordinating ligands, reaction temperature, and reactant order-of-addition strongly affected the morphology and composition of the reaction product obtained. Crystalline, straight, and nearly stoichiometric CuInSe2 nanowires were most readily achieved using the single-source precursor; however, careful tuning of reaction conditions could also be used to obtain high-quality nanowires from multiple-source precursor systems. The CuInSe2 nanowires are strong light absorbers from the near-infrared through the visible and ultraviolet spectral regions and, thereby, comprise new soluble and processable “building blocks” for applications in solar-light harvesting.

本研究首次通过溶液-液相-固相（solution-liquid-solid, SLS）机制合成了三元CuInSe₂纳米线。研究中，金属有机多源与单源分子前驱体均在熔融金属纳米颗粒与配位配体的存在下发生热分解。前驱体的特性——相较于预先形成Cu-Se-In键的单源前驱体，多源前驱体——以及配位配体的选择、反应温度与反应物添加顺序，均对所得反应产物的形貌与组分产生了显著影响。采用单源前驱体时，最易获得结晶性良好、形貌笔直且接近化学计量比的CuInSe₂纳米线；不过，通过精准调控反应条件，也可从多源前驱体体系中制备出高品质纳米线。该CuInSe₂纳米线在近红外、可见光至紫外光谱区间均具有优异的光吸收能力，因此可作为新型可溶、可加工的“构筑单元”，用于太阳能光收集相关应用。